SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8dbae930657a3ee63b9c95b78d134b423ef23726eaf5a4174be3ba693f08357b' 
  AND token = '04lMuIUY0q12kxTFDkcF0XDRSwWwrx2s24pV/UNu7cM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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