SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '430dfd23ce88515841eaa3dd4d2a7dc5b4a39f176500f6183fc1fa8fd28bddb7' 
  AND token = 'EMaZK0v29U1pvPVYzVEmVyQcDaTCCdrMlfKiHcdRP7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}