SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38b9923b7bde144012068993f50c1033a6c2ce920a3fb9a3b8ff0f240e857159' 
  AND token = 'MYcikCBZ4zT1fnETPqFt5QxrySeaMlwswiV2lv1YRZo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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