SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c4ec932b2ed089e88bc17fc94a0a498aa2d2ee4afc109a102990e910f703605' 
  AND token = 'gTBocbI0xbP4x6LEmP7LP6MGIzZhJMQiOo1smSejzyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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