SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba9c41a93ea52b387a94f4f4412be4b89dbcb7cdd98693c1a1193f27a012b5af' 
  AND token = 'uf7MB+FpU8qYm62mTcqPUwfDGvj/9ALBhz7WpYPUMZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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