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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec9bb042a8bfd8e47ff17e6b822c8a45bbfbc323e3c52362caadf3aa36cb9645' 
  AND token = 'iGQoaM+l3Nj79kNIYxjRKkc56wiNP8cb+RLrNnNeFFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}