SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '84cbd384f056088b92ec14c585535540648358173e5cae1a8db3e47f945e936d' 
  AND token = '9ZO9SX2J/MMm3OF4gShqJl1E0gYdlKIKJzsHlpWiQAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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