SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'aceb5cfdc145faea5e7514db87cd4cb6e1f3d297467818bd8ef4430a9120abb8' 
  AND token = 'inZ4K91EZzd1hLo3jCfA+Jco+fjYjcpgtZ+nkWWmbvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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