SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '425db70e9d026f5f2f3097c8daf89ecc34f28a459b51854bbe3f143409255ab1' 
  AND token = 'AdmyUlRxM4GizWnZPF1fBag39H96HeVxIX1ZfUiAkKk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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