SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46b4adab2ca4be6f01f2ddb96a7785b0ffbe7395474ad3a8b0b70a7ffa39da75' 
  AND token = 'ErukOjjbPVtKggGOp5O/nsybhZoevpqTOUuK8BzD0OA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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