SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf5b6601d25887a7f417de09c9d1d366d9eb61b4132095a8540d9116a363c97a' 
  AND token = '+Igpm//ZXJLqVBZw/NiGGUI0iFq7tJQol9KO8ridEPI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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