SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03f2ca3e6660017808fef82c99aac210ca5f6fbfffd877fd0711aff7c2016909' 
  AND token = 'eYqPyp2DLKheVCG4bvoqSGj6+cGI+dcyqgOKX4u14yo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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