SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e3057b5185d3a6aa540a146ee0b7ff746ba42b48a95bf7ba79cbd550779759a' 
  AND token = 'OF6f5fpTrezQZrzqMruzTL0QPHaZvbOqSg5coDs1Nu8=' 
  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"
    }
  }
}