SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a632baab2c2ad07f0e85230913839d112483abeb3b402148506d57a3202775e' 
  AND token = 'prOStVIle1qXxjhfA+Bx862TiG2laJTDPh7vgUQK9GM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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