SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7b2c92f58c8b4fc4c2efa0186c9a20c34ddcd607d68709847fc7cc000cee069' 
  AND token = 'KhxoF5Tn6JXnRAOqpaQppNcTDSllLJ1z1ULvxpxX7TM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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