SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a9ab88e5cafa3d2f34678d9063f017202753eebad07910f57fc6712a6766cdd2' 
  AND token = '6tiF8wV8UrS++dOYBZ1m7L+qhBvt6huS1ksAU3qb4LQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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