SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7067d975e4dbee6d105d47c4d3dfdd063c4973f69f9f596013b84b3e02b61445' 
  AND token = 'gzw3zre0m2fwumhq8pZv97YBihdR3wXMWa0XRu1XIb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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