SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d9ead3db3228f119bf48fd59f8667226ce1374792b3aaba92f9199a56f03390' 
  AND token = 'uQAXc3GDZXyaS19EDiGPTo0YJ03lk0sMbACVKF5lCjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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