SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '911d99ed8d95ce040f55224c3bd2c2a0244c3099c441192c34748ede91c0cee7' 
  AND token = '4VXGPyqzo5ZMLZ5OdQr2qr3y5xzGKok3adqnecbjwso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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