SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1e4c8117f8d4db4bdb80d7498d72b515bb8d408c4cdb4714cfedbdb224241bf' 
  AND token = 'L6waermhCW33PV5TNmuTksLvgrvy9u9SlzEvdZXTl+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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