SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce52b57bc84c11fb134f44b01e07d846a65e193f0736c9799e9fefb363f5257a' 
  AND token = 'TWPiM8ASvFehitq9xHApslg2zPwqR95BdjZF2y1PH8Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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