SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e6ed1aaef9b92b174df275e868154110d2a8e3a1cc2bf9207a28b7cd09d2957' 
  AND token = 'YPkMsivm7rbcf88pNEf8gLKZ/DD2aqCqnIX/o8WVvwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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