SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bb1149886de61bd2c3152d17a99ea0eb92721cea3bbd4ef311033d1ffed35ee' 
  AND token = 'Lj0KYiV4GIxBk8v/7wcuvznCFIjvRAPMi/fLmaQlqvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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