SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03afbf91caf0ce9b7b4bd7b84ca5ded3339e25177587e2ff456b6917771cd1fb' 
  AND token = '8l9VKeSKf+ZrcvYsrzQ+2IM9fuHCwz9BTCVZzvtjWc8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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