SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e64429b6c0d5d1369f784aa0f8406ee4f9c28641603d210f68da7f0a52414f18' 
  AND token = 'YKu8XGFvqWPohiHBUcf1Rs7IeDyg/6OXTJi/KB+oLeU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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