SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce85faa7294e2e2513736170f65199a34ab03ed9451cbcdb150fa9265157c896' 
  AND token = 'uxdzh+4iy0I9x0yKjVwhQ7YpL9v3zIfJ+wPVc/6jkJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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