SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42c10e61389e67713dc3d3aff24d59109cfc56592db591c39a1ae3ba4fde0ac7' 
  AND token = 'fLmnf+Vy2b8btdhMCiez//+wGQD/wjuCQKFy53NANg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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