SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0940495c6e1a54aba1a6266c23b938d2e3c37363d28f147f453904818cf24b99' 
  AND token = 'NzU0ptMmTQgx+avzJ1ty2aPX87gNWGYi5gcfKJRNRnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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