SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f7e7059e787d1b8f6bae729d51b36568b7d532a092f029c17703e08170ad42ad' 
  AND token = 'Zzwj78bLW0vbYic26Pg4UBiD0V24pYR+3Z00RL69alo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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