SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6e025891fbb24bbac30b84034f47ed5b26c19c23dde15b615f89b9ffcfa9a33' 
  AND token = 'yOPkf4BI+6IXSEdKgEWLmGwCFHLedScKPgSdIcAq5a8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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