SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6166d71fe22e3301e8d0ed9fbb4b9d82d9006e86d9d6d8bd9d3225631f3ffd6' 
  AND token = '2CAIQsxtyclyALn/kQleZV08ZHdLwkbWGIFo5nM16EM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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