SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e3229bad18f2baa22abc4b898c8ec27617d7aa121b3c61628bb477a7bfc54f1' 
  AND token = '1+rPmCF7Ner2iRdBdNvGHoPiCdi2sCEibweEOcrufQ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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