SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e9ad832d24661a508cd16c5ea0ae51bbda16e1e95439b45d75fd55f1299b998' 
  AND token = 'U9OhvsTQqebFf0jg/tRgSZGJJ7wi03FbtThjUHi+qvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}