SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '057ddd65bd025085aca062ad8741a12f31040bf30f6ad6c39f306298460323f8' 
  AND token = 'F5Pff7tDAa8fuMfjSFWXmIAVn/UUm/xColnioTukkGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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