SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c16617d534148bb07693110548687c24d815cfe361835b9b74ffe78a2417c2f8' 
  AND token = 'tvgeoPyUhJSLDZDza9VrzGWeSBOStzlDn6QwdJLAQQ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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