SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da57f7040fd06b360743f313b5037e3c8ba5dec7c69aa8dd25963d7625574d29' 
  AND token = 'Lw9T9aBZQJrvNR48gIfIXKUYER/Hjqow0+L19NhKHvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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