SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38e6d9176cbc5e373fd65801b7ebe700e2e0ea479e49121a03d2637abb2c6f2e' 
  AND token = 'mmnqEW8H618rg/N5pp8S+99KLGlZ+4pEWa151s0EtCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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