SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0aa8dfd99e404d4f585f36f426c61573ff5df39f4022d3d5c9a9dcf1ed51a919' 
  AND token = 'wB798aB9UPKK+CJqzUERv07n8XPbg/TanYhaitzaLXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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