SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '442f70463b7859c2f82d74fbbabf34b13d1483d40c8bb593fdc9ab20594b6edf' 
  AND token = 'dh9iul+1z5pJa/sgMpj23MeiFY6w2KRZnfmIYzFxbi0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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