SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '27c06412d34efca1f5f3d1e76b1fc34c7cf57c3622103efb678d1f5bb68413e2' 
  AND token = '9jBi3oHX0v/1oKJwFBuLeijqsZiF0nvCBC/Ro+JuYto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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