SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1241620232b07106c61d957aae459cf439d6eb759e1811b1ad9ccd5747ba5b6' 
  AND token = 'dRfAMZsgjFOMztHG/9YkMgDM038VBtK/Tg1Jg4QLeUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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