SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6ffd2224968fa34aa058100940b43af32bfd3ecd506140f4f43199a720b9c9d' 
  AND token = 'Spg1f6VHUO2x7zbyooxItJhBDwHqsBhT8hWb76EzJ88=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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