SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a053a53f298b4c214e2243750ad561a2e65c7fea6fb150046852e3bf6c146a93' 
  AND token = 'qMZZabgrOQgegNeAtvxtohILAkIjXTY8ESlhOX3qgLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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