SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ff09832b1a5419f4f812a354a2fcf987d8512fc9e9f33e88005d94f4635a5d1' 
  AND token = '17rLD636KKGVoRShOkeZ+79ZVH51yZqJN0AcTg5sdaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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