SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e64bb917f9262a3f798bdbe052604e54a9f3ccdf601d2568451fbde32f47619' 
  AND token = 'd9Gu3yXdUYo0BKXMbgoegMgTFeOlINZMf+/+CtvbAFE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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