SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '426fa5b789dae25e78e6c8561809339d9737f766ececf3db2de0ee3811a199c0' 
  AND token = 'RY5ME4Wrm0Ljv0VeBwX5Tzig2DscXNL2gDWNzG4N/R4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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