SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c62cffdcda8d973d2640485d7bd85b772d0a9985e7366fafcf3c29c47a3d1fe3' 
  AND token = 'hSIHFzMqHhJb12kDyx/LewAQ3DkafP+OyKLNXEB0tMc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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