SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4d36f4e214f28a3533ff15ca58b66329007831f7f275b8a01e0e15fefecb995' 
  AND token = 'hpz6xz+OEey5x05mpUsDuhj9PgTrrBbtc5nxaZOQZA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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