SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf3ff9ff73afee45c2c6d70b69cf71e271db1cef75f44b2b34da9031fd164f64' 
  AND token = '68pDQdq2eA+25oVxJgASfRuTixpZzplNos0P73zYzYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}