SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffbbcfa8d6bb145d592be33466abd2730987b04cf49f83971a6396efd840a896' 
  AND token = 'ndxV/5UJ+7+Zlxl/aP7MEtwyYPr9mHrhFgruXPXGapE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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