SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e90960cd066078fcfd2e5f36125e536b60b69b1553727e173374d00760eedfa5' 
  AND token = 'JeAJQGmlaFIHkaJ4mzaZtQtkJbIbsoKLTuTo7K6KaIE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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