SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '637a747f51c55e88a2ab49a866aac6e9c29d16ebe74e21e4f7ea74c605e58592' 
  AND token = 'LVLwgEI6OG49QpsgkOJBbAjmqTomrOUjJm+d9KzxXvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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