SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9638bd5dbebbde8b4220d526d78f9d31ce3c317ee771278116d6b6450fb43eb3' 
  AND token = 'Cti2RFuzHLTNt29hFbNHe+rlLvrxrneN9dZyC0hJKnA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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