SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '100da10386ec292f5bec526cdc1da3ab799feb5cd94ba636555d1bca57d9573e' 
  AND token = '0mkKrx7xrqAPcunNgJBwBGO7epW6MvwXhT3wJIQt3ms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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