SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f561a204269917188cda08001c44efd56f26cb45989a881c7f953ca77e37698' 
  AND token = 'BYaY8w5KpumklPkYOfPEFqy4IK9INnQTjmKXxDmO4As=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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