SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'db11130fef0ea33b09038ae8ac3214368a6458e6a530cf868d1e48673cb313d0' 
  AND token = 'TPNtBNlN2H4d3h20VLCYseDtn/zQ/sVFXVci3j+hYfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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