SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '89e198a9e914773921da74ef5de63bd3d9eb51e36d7519313c1c5cc25f17d626' 
  AND token = 'hIBzXt/gKse+Nhm/4nln9QuV4P1mZdy8L85UpcT81yc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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