SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45f965384bb1659dc28c31d7c5f9de43413424e3b13c98aa2f9ccda4bea1f70a' 
  AND token = '6YscRcblLcbinNoArjsHAHHKcS1wuZaWisnYnIEur0o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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