SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4104695292d9317a2756d7ca6a5bf927d8183049deff61fbf3a78155a8b4c083' 
  AND token = 'EZeYSlGtV9dVmR+QtBHuaLEX9XyfuLkOGPV40/Lh6MY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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