SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '015c0d556ad531270dfdc8e6cc35ea18ed96f003892db91db91116e5ca1695b5' 
  AND token = 'ez2U3FwltBLHgUOGeNweiFBfy1pSRbea9bLX4BHMPj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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