SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a87c3be639c47fb58c8e1551bc18b790702205d8a57a3b4d744754ac8f82fcec' 
  AND token = '3WyuGLgO7kCV1p7US7Z5JuKRZlOP+9Ffj6pZWv+FFCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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