SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a585b5ac5f02681de5f5a25bb211a66d5735f7a3249eb439a0c0701463ad6b41' 
  AND token = 'm1hxfeYDYkW2KBqhrLa/kluARpMhYOTVvFU7cDfJQ3E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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