SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f3fa480425f71fe1e2ba811d08612cd3bf587f4ffaf4dcb1ed4a576284d33d3' 
  AND token = 'Vs2iuGH1SxVIGFgIqUPxWBdZLuzUSJJRNo9lF1gKW+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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