SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9799780f46c5de024c55481dbba7341fa76b2a368ee209b0e27e415d3b1555fa' 
  AND token = '/OhAGf6ReqIGWuYmEKkBFZM5vDThpo0XfzJ2GcyvAwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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