SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '736e2e43df618fa50e4ea0ad0fdbf221bf3af49e76cf21cf32e75249ee25743c' 
  AND token = 'IRGUE1o7MKk0fxHx+TNRQmfcVq68Ka3z08DMPxlxw0E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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