SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '9a0041fe635562b34d5262853fe4c162a6c96ad09d389b00a7327296cf9889af' 
  AND token = 'YH9B8EcFu7ntoeARiIPaQKTUKdpLwOVOAOIgu290xOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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