SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09d19b0c2fca511807ee97c0f9287076e8b76bcdc6f790a8600c944d07cfa487' 
  AND token = '7A77ygdAQj588iFKKA3e0LYOmXRIGPzY+yjUxLnJ4dg=' 
  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"
    }
  }
}