SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b52ce268e7b8f2314ffdbef731bb691748f8245ac164a5dcbca7d5b05786384' 
  AND token = 'VzMtseajVdaZX8SxRASihuQmpcWKyMMNt8eFPZRE9jU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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