SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebb1bd6fcc9d5924982307dcda93409cb9e73234124985a3132f48e5857268d1' 
  AND token = '/1uG4s2MibvlPNCSqVBARrZTwhhxPvHMGdzLmJAZhqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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