SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b01aa005a85ebc8b28ff5eecfa430bc8d55c514952648b31d1686a1a39f67811' 
  AND token = 'Se/KHpAMPiiTDHtvhoszcOU1QZ/ZgCVW/XLBUFCx1tg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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