SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0f0159546b4f58ff783aabb6bdf02496350ed5fe3a3557261dd5cbb99a645b6' 
  AND token = 'UVRkLOgAUWiqIZdlJiGb0jiN7Ru3H3CADEmKdlyf6E0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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