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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b16b7ea3792b01ce5f102799238d5e3e63d5ee0f81d0b6d82bdf4a742d2b56ee' 
  AND token = 'DfZa8bHDPTnOlfh57lxxUIkg94sqP9iGfnuUao2KK6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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