SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db7cb9deb0999000148f24a766d32293b04902baccc4f8e2d2811d62a8b272c4' 
  AND token = 'EIlbM/Qan0tDaEa0XJweuWmUwV625wjLRvwCNJoQYLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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