SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '317fbcb2175610944f7ad7ec9863a8bb8b6a2367fb6390284c0363087a207f43' 
  AND token = 'ZOwQ5ItaSeYuKg5aMYY6owNkdWcyb1qiF5mRbZQOwd0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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