SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b46cece10a2735305d621fad3be5690b0e92c6eacdccfeba706106918259199' 
  AND token = 'maTg8YJwXaiF/ecMw90WgkDYJ96hN5fQhDOF0hFtuqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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