SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a88fe280d5d641e7e42fa26332353652c7d61d7fffd912d28fe43da71510fb01' 
  AND token = 'DrrUB191arS8PyI3WvjaSwOVghMkGjW5c0m8YQG6rK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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