SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4317040c1d494c827c9ca0a391a314bcc7d3b9c87d63dda23009ebf41cdd4fbd' 
  AND token = 'zixbfp+o5TvTPlHk8pcIwj1oJnh2fFcTwam5zAGXVXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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