SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08d052da3035c768330a49ed48813ece84e49e064a85e23e50e1a412244f54b7' 
  AND token = 'Mv/F7TMfLnUfXpNTF3QruTHQoJzKjE4x/MkiLGjLmM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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