SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b6d8bb204bab3bf77918884aad291fc6151a2f9c2a6cee617065b85697c503e' 
  AND token = '0XjFJfAkp3fLvtQe8Ml5lqxPhqqd3tfRlirCcBEUBmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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