SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5db51cb5077bbb76e24e13df327269095db1ef8ada963ff64dbe368812330cf9' 
  AND token = 'p4fs0juQug8aXaMiEU0EwD53vOFMO9LGwaBuaW/JYKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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