SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd5e746b552b9aac70348441a95a3bc5b5dcc0d3f2caefd4fbd6c02d609f24493' 
  AND token = 'wO6Xqpt43GYP8XczOsLGQCFh2Yc+TZGwtfW6h1X/WDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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