SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '946fa9c35a34e7661fafc08271307df199179458f4b8eabb5b6fccb784f28d52' 
  AND token = 'pBKPLVYf+efqEznWi02NlX1p3gDi9Fbjf8629u7ABtw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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