SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '423c3cbcb281bdc5f51a497fdb6cf615f0823b2547ab5f4172ddccf28175fc40' 
  AND token = 'QeKgvTZ+kNAADrTqziZ2J2gpm9jaJF5uYoC/p1h4gCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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