SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fce8f056659547e9e2f146d97aedcd09fd34ae6561197498b71d6eac9449244' 
  AND token = '8caFZYjP0yjuQ0UMlqrObDBA1WXNdap8LUAXS8rEQAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}