SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6dfd9de83154c1ca74033011f9f5cbb5503a387cef9c92f56c668259084d1570' 
  AND token = 'Tli+heVhwBpkhN8kJTtJk3KiXdNPJBHsSW68v+uzHSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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