SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3054b10d8c66868fd3561e2d044bfc635160370358449bbd54942db81878f258' 
  AND token = 'SSIFVf3CNHKUwkPh0NDC1JPPs47wyvBV7RS+7QEn25M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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