SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '468fd60358bd3ba5cd847dea0264244a1bc017324ee9082ff05105c1c32a037e' 
  AND token = 'CVAQi5MUEPC0Mm+76+MkCZoJA5jqnl/FnXSwAgFaN3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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