SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '183efa67763491fef1ce70c21e36eed0725398001ea5f9943a314781649ba47d' 
  AND token = '07FlGEnp++FVpBnYIweheyjr+fDKfpRDZdfKCr5dSIE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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