SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48ead023fd47f4f199f699a411722160a617b855403d92b2b3cfa7142c9234aa' 
  AND token = 'lNdW5VBjV1pGfMi9GgbNd7Y6A3qBDKE+tXXOozQfREY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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