SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05c05f6378f7246adc280e077008728eccc3269e9ee30d753c3834c9e0e0d942' 
  AND token = 'fY23kcjbJja0oEiPqeBPjwWSG3Plh8cciGLEy+sjOtM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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