SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bfe11a780a14b3ffc183da7e1bd0b4e66bfa7a831ad0984de4fda5335bc5b52' 
  AND token = 'tiCfEYp1iVVfC98PhyOxHYrkOT88sWGmbFtnTQ0sfVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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