SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e048114d2eacec226923bcc01a8adde8d6b98132697f9873155b45fec9873d99' 
  AND token = '/+4Rf9KUaq+k9zVVTHbyPewLpWGuDA4m7jFUwnpdmuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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