SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '575057a0f81e105d19fa23a4212867d80585d2d4a20cac797bf13773d96979be' 
  AND token = 'lQKNobxUrGRSZYI5z8DB3t9fZjTfDQZpYJ5Z1vGpNew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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