SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59f177a9d8843cd4704b143b8d52f1f365d624b7ea5644f5a4ae03523820479e' 
  AND token = 'E5Ng/kOZfjBa/w/Y8UUl+WgcBC95rzgUTpnwxHfDUOc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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