SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c88fe10eaf7f0b1f47e822d6163671ed014b017226796b4701bc7437d752d4f' 
  AND token = '0jUC9L8oXyFafAqMgssQCotJ/VmOlUoZaxtJOhtaOV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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