SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9c96feadfb0ca0c5cef80571461ddadb1e91fb8723a6f7832809478ccebde7b' 
  AND token = '4gheKtFtqVKPAanqwK0hU8sVQsaLJY9moKDpRLyJ3lc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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