SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '989cf4ca97efc5a752f35e0ef9a8121151f28f44d4a30c10476781ce2e0a569e' 
  AND token = 'YvOn5uUojOQISWmifqRYqHXYU9HVhO6NABiApgGB+MQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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