SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffbf0b4ef8bd54356f2722684c7a38769df4e6dbe86cfbfaff155470504885e3' 
  AND token = 'GfAuRVT+3HzzNVfrwb5gh7DgsiBkjYV+3asXQxOPOdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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