SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14c4ac648a4090e283d3e01663d403fd1879dd7ae70f2127e84e0a1ddadb2fe9' 
  AND token = 'qBGCGMnkkpTVPm1uKAJMSSscNWPXYdRYMqty0hPjszQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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