SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3eab75bcca7db7c204938c9998359b6a277f884ab7554cc06a73383433bd9b24' 
  AND token = 'E6xUe4XF2pAZgbjzN3OXw8XTMooNDCyiL8PXz/bO57w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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