SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6567bc59894807ba69854563837f39a314d7fcc622e44caeb52ce5b5e554ddb6' 
  AND token = 'xsjskFFSakSx/YASMoWCyrRTdSt9ZnuyRf8BuxZVrkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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