SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd43e8278ed553307466364f9521064bf699221cdfa99a64918c5208579ce189e' 
  AND token = 'BdilMi1/leORzJe6Ho+ICkdqbqP+I4gLWWFtNnvsYi0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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