SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5952dcfe671bba987da74cb151c149bcf0cdd3bb62865f89ae89cf944865e05' 
  AND token = 'XIWHJlAZJdAt06vg/SWLSl03bVGB4O9YjOBQl+7LfBE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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