SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64158aac03f1b787cd64a36cf44b0561507bdaf6d9857c48832887642eb00ffb' 
  AND token = 'h8KRjCAgQK/hZVcY9HXo8V05vNNi8agW3gnv285JkrI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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