SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96adb97367713df77134879c9824147cd6f0914100a4d3cba8fabf07be338b59' 
  AND token = 'FNQbdaPrLRjXuZBvKHcVyjlkMeUBEvtQ6LLJLZiu45k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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