SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b470b210a3d953d1ad3574b4e290305993c10ff3ec3a8203ec66e228c3eaf97f' 
  AND token = 'GIcXMrQPrCei1eym7QSWpE3jbAFaCSHEEqcF0/XewyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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