SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ab195c514b69df10efe19138412650e59b861b34ae46ffc112edd37d530477b' 
  AND token = 'mMFgEGsOzQzJSNamx4EHttqR9DPPikoS+9Ls+IHNTuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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