SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff9fdaf04fb23178d227785c8f654fefe75eeea26eca63aca0fe9fb8b1729153' 
  AND token = 'GeJHEGs/rnM4jFY1KJDBn11fYtiBr2SLXS9yrwa5JMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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