SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43272029d20f9453fdc637f366f5fe933704e61ea920ce858d38698ddafdb842' 
  AND token = 'bSsVmL2hoEcriBu3KbxJ4VRu4xzkz1RhnZhtLE0zGK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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