SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc49a23c502dfc4d135c888457a87f45cd08f61b47b4c66b3687595388f3c215' 
  AND token = 'hjgYYaHmdYnKvYBf8U1Qx5slJi17qXGivCW2A/uvOJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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