SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb32054758e64f051269a4596abc6e50faf77eb4ad4dc59b966bf64656bcd624' 
  AND token = 'HYdW4e3HcOIQLTcCpmo+81GlGK0lJvZcEjAsKyn4r78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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