SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad6d98818bdaebb3bbf3aae2d53e194cac237bb49aacf95f117c1607cb95f13a' 
  AND token = '+WIHg9mBhSECAS5BpOmdpCkrTNsaUcra2p6CEHBsnUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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