SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba9d5f0dac12594889556df2aa35662396f4f84655649ab24a980ef9b2803e43' 
  AND token = 'V3CG590YaJJExa0JX2KeWxWW+fyYeiWBg92uTcgXjTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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