SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4df3f3f2c6879204ea28761f1ed2acedc8b1854a7602e2ef2de0bd0fcd15c24e' 
  AND token = 'Xu8VIMdlLCMlhUW2luJO/amUWI/nNJgVhG6EINCVoSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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