SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2f2377cc3857cd008a0c9d8ff42977c08002e5e970b216b850dddbd6b63df02' 
  AND token = 'kOz8oQS/K8TJjYnKGBO/CXC7yONzJuZVvhKLRxwR0D0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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