SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34722d8d8675d67401668d75193f39db3a12c309f9f61e0e88a26691e6d27720' 
  AND token = 'JjYjn0MoKH6Ok8psrlcEWtvtKDzY7brRRybMp67iKEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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