SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '609071377596264c1e32c0dbc0b1b3d6bbddca80cd3ca1e06afc2ba867217e6f' 
  AND token = '+dIGuDc/1bDJNpkXupHVU+KBktBhpVhOnQVv+pkliII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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