SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2697463045dfbf091081a6a1c221462798fd0abdf7a9e56786faf29c7b739763' 
  AND token = 'Zy/KfjLUAQ+mEyrG7YzvxmIsjahfRMmXs0gcxVbhu4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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