SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70f175732df9f63e7f6b7aa7a9a8a8929dbe80419e515b5a34a364b3a8efc25f' 
  AND token = 'I7GDObNPy/jwrzQ3VcZEtiCjoIfDxzNWvR+0YO+5qSA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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