SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1984bc87d752183a74dd124c3b28353e6486f91209ddeea49e9f6ee3d283662' 
  AND token = '+GogXnOJSvU09eiDqyUJqHUtUb6wxZrVCk51f446plE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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