SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04996db6947042e6a2a93fe91cd342b7e30fe2f3a4d58c60aa479491a34a1029' 
  AND token = 'litDdlKuAzsvdZD+SmNUALHUdGgSVakeyGwv2w6Bc8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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