SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a426c22e1210f9da14ea5a3787f6838ab1ce76e282ab3de5bb168a052b2f0be6' 
  AND token = 'Z5nHVBA0qkJJekhNituVKzt3+8QcPdLXIJlYxE7T1T8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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