SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa7b2526b1779da987665e7525ab9c465b531773b4f16711a1f22377b72e81e8' 
  AND token = 'wQoVZCM+kaEGhaZrHjYh5MIDyHXMgfMvu8RyK5pA6PA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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