SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c96f452266c028781a34ef0dd6675cc1dd8b65eed2c774b8146322773a0c73e8' 
  AND token = 'CT0CoQypkHXVzE6nrz5G/ZM5mZHJ1VaxFOZ+Wji8xq8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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