SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '338a0e0084aca9f9ef6e9783eac9bb6cb83180687983e64178dbb36ff3e39083' 
  AND token = 'BmTDxMK57wrr1w6U/+KNRZyr0wNUczeGtRERM22Wl5A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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