SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d83056245bcf8f77bec0a97058e163bfa69ad3f8517e969e84755aec895232b' 
  AND token = 'sPwJaMjiVwWBc4uUCk0JIORw+jODJMP0q5DTvr/VBj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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