SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33af295bbe84d4c4d616a4e53ee2f50d991428240eed0c9d2ec4194f2227cfff' 
  AND token = 'X++Z4SgMJS4bRlEGo5uGXw71995oNi/bReZyTxImblI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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