SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a78a4452927e35c77a6ebd175f7935133881fb6e11cd2a831fa310b6a06e860a' 
  AND token = 'WWAIQB3/MycbmP2NiNnmOkuK355W1reWb4m2Zro1I40=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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