SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4f9dc63972d7cfb00eb6553359310fd19c080877bb74c80ee8da45cd44f95a2' 
  AND token = 'l7VDAjXIOIrxpoJzVsh/HPrWY7U8DIm5gvDvjZFwOqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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