SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f0f1695e4a227c54ad1287e1067531a69bdb41f0c6c370046193c56ccece666' 
  AND token = 'XcOZ7+OPqDITTqfnZv7UuOPS6TNoSPajBzyBHeHYdjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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