SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '316f1a6a281c219628109b1ea74059b494cd93e31989d8c150a72f1877350f16' 
  AND token = 'McF7qUmP58tOLsFlnWroTRnVlKI+KAh80/8W0E0raxw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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