SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2d487e70f6e10788205d951c773e8e5db13f0cd95029078e16f481c6cc4c54c6' 
  AND token = '9jsEo+WRAJOf+oYO4kshVNUG+kkZfqlDsUPSrR/PQfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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