SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd40be79037b06f5476ce17a628a46065a8ce4c60881852281e0b076ac8ed83c0' 
  AND token = 'qLp5+x4S8/+BaUo8V3NSIiTSuCe6dfB7uzIPU776KjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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