SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfa85500fcbd853d2024572592f9618c472ff7f814905c1878fefd9b19120ee5' 
  AND token = 'hYV+WB9OauxNCYat2w8KILLOCoR6u3vRJUcKhYiR8+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}