SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '290b77c1f0106395d923ca803c00a0e0ff4df503bc21f16a22fe4bc124aaa374' 
  AND token = 'WEbmbscCU52bbs3gdZl6L3qzwGaLTe7fbxv1zsALWM0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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