SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca4b8e801df1fca7c20d46e0238f8fa182183a27ce129c41b09294678870c6de' 
  AND token = 'YrhLgXNOAOUoECzlbUv+KRi6gdoOVqvUyPPWiaR9g8g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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