SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff71699d51cbf8a0d9430bcf00822c5476137f0dfdf838245fd05b326705fedb' 
  AND token = 'aPfl+TN2iOJY3k//KkpzPuILE1VxXjXPD9B0PFXaDzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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