SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf78483760206d87e9533c391585ae6be4ce5bc8334e958cabdde4e2d9624364' 
  AND token = 'azMqJReoWkbh7QFRY7oBgYFumNZJG/XN9Fg3VGnrPJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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