SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1977c7c8907de0f465090b18b48f898f0ec3ce50a17d99fabc12e55e1b004ecc' 
  AND token = 'pKaiby1khpziOWfXAbfXMX/qz7YMJucLctGbN6dfuVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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