SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd0bc0a3d4c827b60726cd7318725135c9329c23b2ba3b36f82595d0cacacbb6' 
  AND token = 'z+5wDMbiI5Yyx9Erxh0be6dKyDNLOJKUiObV0KbJS0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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